This invention relates generally to fastening systems for furniture, and more particularly, to a fastener clip for forming a joint between furniture panels.
Many joints between furniture parts such as cabinets, shelving and table installations are fastened together by concealed mechanical fastener assemblies. See, for example, U.S. Pat. Nos. 4,332,205 and 4,178,047. Many of these concealed fastener assemblies employ keyhole type slots dimensioned to receive the head of a securing stud.
One prevalent form of fastener assembly requires a recess to be formed along the edge of one of the furniture panels as shown, for example, in U.S. Pat. Nos. 3,451,362; 3,634,983 and 3,645,162. The fastener clip having a stud receiving slot is mounted within this recess while a shoulder screw or securing stud is mounted in the corresponding furniture panel. To enable the head of the stud to engage the fastener, the furniture panel having the recess is also formed with a laterally positioned window communicating with the recess. This window provides access to the recess, and is formed adjacent to the end of the fastener through which the securing stud enters. To join the furniture panels, the securing stud is passed through the window into the recess, and assumes a position proximate to the slot's entrance. The securing stud is then urged along the slot, which may include an inclined ramp, to seat the securing stud and thus firmly join the furniture panels. This fastener assembly is often referred to as a "non-locking" fastener.
Another form of fastener assembly commonly used in the industry is referred to as "semi-locking" fastener as shown in U.S. Pat. No. 3,894,377. These semi-locking fasteners are of generally the same construction as those described above. However, the slot of the semi-locking fastener has converging side edges which form a narrowing width. This narrowing slot is commonly referred to as a "throat." The throat opens out to the seating or closed end of the slot which has an increased width portion. During assembly, the securing stud is urged down the slot and, in so doing, engages the throat to thereby cam the sides of the slot outwardly as it travels toward the seating end. Upon clearing the throat, the sides of the fastener return to their normal position while the stud reaches the seating end of the slot. This semi-locking fastener prevents disassembly absent the application of a sufficient degree of force exerted on the securing stud to cam the throat out of the way.
Still another common fastener assembly is entitled a "locking" fastener as shown in U.S. Pat. Nos. 4,470,716 and 3,491,820. This fastener includes a locking flange extending in an upward direction from the base of the fastener and terminating below the slot, adjacent to the seating end. During assembly, the head of the securing stud engages the slot and depresses the locking flange towards the base of the fastener as it travels towards the seating end of the slot. Once positioned in the seating end, the head of the securing stud has passed beyond the locking flange which has resiliently returned to its original position. In this original position, the end of the locking flange is positioned immediately adjacent the head of the securing stud. Thus, an attempt at removing the head of the securing stud from the seating end of the slot results in contact between the locking flange and the head of the securing stud. This contact prohibits the securing stud from being removed from the slot.
Under normal assembly conditions, it is usually the furniture panel having the fastener clip which is moved relative to the furniture panel fitted with the securing stud. A problem often encountered during assembly is that the furniture panel having the fastener clip will be moved in a first direction to place the head of the securing stud through the window. However, due to the excessive application of force, the head of the securing stud is not only moved within the interior of the recess, but subsequently impacts the opposing wall of the furniture panel. This inadvertent impact with the opposing wall results in damage to the furniture panel. Often, such furniture has a layer of veneer positioned on its surface. Thus, when excessive force is used to place the fastener clip in proximity to the securing stud, the stud contacts the wood imparting a force which subsequently cracks the wood as well as the veneer positioned thereon. Consequently, due to the state of the prior art, operations utilizing the above described fastener assemblies often experience a large quantity of defects which in turn increases manufacturing costs.
Another problem confronted by the prior art when using semi-locking or non-locking fastener assemblies is encountered during disassembly of the furniture panels. During disassembly, a force is imparted upon one of the furniture panels to move the securing stud in a rearward direction and hence disengage the same from the slot. Again, due to the excessive impartation of force, the head of the securing stud is forced from the slot and subsequently contacts an end wall of the recess and thus causes damage to the furniture panel.
Accordingly, a need exists in the furniture industry for a fastener clip which prohibits contact between the securing stud and the furniture panel which mounts the fastener clip during assembly and disassembly and which can be manufactured simply and effectively from a single blank of material in either the non-locking, semi-locking or locking variations.